This is a priority application based upon German patent application 100 00 697.3, filed Jan. 10, 2000.
The invention relates to a process for producing packs with an (inner) wrapper made of heat-sealable sheet material and with folding tabs which are connected to one another by sealing, in particular for producing a cigarette block for hinge-lid boxes, the pack contentsxe2x80x94a cigarette groupxe2x80x94preferably being enclosed by a supporting insert made of thin cardboard. The invention also relates to an apparatus for producing such or similar packs.
The invention primarily involves the production of packs in accordance with WO 98/22367. With this type of pack, the pack contents, namely the cigarette group, is enclosed by a sealed inner wrapper with folding tabs which are connected by heat sealing. For opening the pack and/or the cigarette block, the latter is provided on the front side with an opening flap defined by weakening lines of the material. Provided In the region of said opening flap is an adhesive-bonding closure tape, which ensures that the cigarette block can be opened, and if appropriate, closed again. The application of heat and pressure to the sheet material of the (inner) wrapper is problematic for sensitive pack contents, such as cigarettes. For this purpose, there is arranged within the cigarette block a supporting insert which consists of thin cardboard and encloses the cigarette group in the region of those surfaces which are subjected to the action of heat and pressure in order for folding tabs to be sealed.
The object of the invention is to propose a process and apparatus for producing this type of (cigarette) pack and for producing similar packs.
In order to achieve this object, the process according to the invention is characterized by the following features:
a) a blank for the supporting insert is positioned partially around the cigarette group in the form of a U at least in the region of a front side and in the region of long side surfaces by U-shaped folding.
b) then a sheet-material blank made of heat-sealable sheet material is folded around the unit comprising the cigarette group and supporting insert,
c) thereafter, the folding tabs of the (inner) wrapper or of the sheet-material blank are connected to one another by heat sealing.
d) the resulting cigarette block is pushed into a pack, in particular a hinge-lid box.
If the sealed sheet material or inner wrapper is provided with a closure tape, this, according to a further proposal of the invention, is applied in a precisely positioned manner to the continuous material web for producing the sheet-material blanks, and then the sheet-material blanks are severed from the web prepared in this way.
The apparatus according to the invention comprises a continuous pack path, in the region of which there are arranged conveying, folding and sealing elements for producing and sealing the pack and/or the cigarette block.
A special feature is the folding and sealing of the (inner) wrapper, namely the formation of an end wall from end-wall tabs which are folded in a specific manner and the sealing of the wrapper such that the geometrical shape of the same is taken into account.